Winding core



FIG. 1 is a perspective view of a winding core;

FIG. 2 is a front view thereof;

FIG. 3 is a plan view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a sectional view taken at 5-5 of FIG. 3; and,

FIG. 6 is a reference view thereof showing the actual use.

The portions shown in broken lines do not form part of the claimed design. 

The ornamental design for a winding core, as shown and described. 